1. Field of the Invention
The invention relates to a lens cap set and a lens device utilizing the same, more particularly to a magnetic lens cap set and a lens device utilizing the magnetic lens cap set.
2. Description of the Related Art
In order to prevent a lens assembly of a projector from getting stained or scratched, a lens cap is usually provided to cover the lens assembly in order to provide protection to the lens assembly when the projector is not in use.
As shown in FIG. 1, a conventional lens cap set includes a lens cap 11 that is provided with two hook members 111 respectively having springs (not shown) embedded therein and being respectively disposed at opposite sides of the lens cap 11, and a mounting ring (not shown) that is adapted to be fixed to a housing of a projector or a lens assembly of the projector and that defines a light path in spatial communication with an opening of the lens assembly. The lens cap 11 is disposed onto the mounting ring by exerting an inward force on the hook members 111 so as to press the springs and move the hook members 111 toward each other. When forces exerted on the coupling members 111 are released, the springs included in the lens cap 11 rebound the hook members 111 outwardly by virtue of resilience such that the hook members 111 engage the mounting ring, thereby fixing the lens cap 11 to the mounting ring. Consequently, the opening of the lens assembly is covered by the lens cap 11.
As shown in FIG. 2, another lens cap 12 can be included in the conventional lens cap set. The lens cap 12 includes an iron member 122 and a rubber member 121 surrounding the iron member 122. The iron member 122 is provided to prevent the rubber member 121 from deformation due to illumination by light beams. Since the rubber member 121 has elasticity, the lens cap 12 can fit tightly onto the mounting ring so as to cover the opening of the lens assembly.
However, since the lens caps 11, 12 employed in the conventional lens cap set need to be matched with the mounting ring during use, the lens cap 11, 12 and the mounting ring must correspond to each other in size and shape. As a result, manufacturing tolerances of the lens caps 11, 12 and the mounting ring need to be taken into consideration, where lens caps 11, 12 beyond the manufacturing tolerances may not be able to fit onto the mounting ring. In addition, the springs of the lens cap 11 and the rubber member 121 of the lens cap 12 are both subject to elasticity fatigue after long periods of use, and the rubber member 121 is even vulnerable to hardening. Consequently, the lens caps 11, 12 can only be used for a limited period of time.